Celeb Spotlight: Venus & Serena Williams

Ages: Venus is 25; Serena is 23Hometown: Compton, Calif.Current gig: The tennis-champ sisters are starring in the ABC Family reality show Venus & Serena: For Real, which chronicles their lives on and off the court

They're happy to open upThe Williams sisters, who went pro in their early teens, practically grew up in the public eye. So why reveal even more about themselves? "We felt like we're positive role models," Serena tells PEOPLE. Adds Venus: "People would be really shocked by what it takes to make it, what it takes to be 100 percent mentally there. At the end of the episodes, we feel like people are going to feel good, like, 'Wow, sometimes it's hard and crazy, but it's worth it.' "

Even as reality stars, they've got a competitive streak: "I've seen (Newlyweds:) Nick and Jessica," says Venus. "There's a lot of downtime in those shows, and our show is really fast-paced. We're working nonstop and are fighting to find time to fit things in."

There's more to them than tennisThe sisters are at the top of their games – Venus won Wimbledon in June and Serena is the reigning Australian Open champ – but the show documents their other pursuits, such as Venus's interior design company, V Starr, and Serena's burgeoning acting career (Serena also has her own fashion line, Aneres). "We do a lot off the court," says Serena. "A lot of people wonder how we're able to maintain a close-knit family as well as businesses and other interests and still be world-class athletes, and I think this show shows that."

That's not to say that Venus and Serena – the youngest of five Williams girls – never unwind. "There's a lot of interaction between our family, like going to dinner," says Venus. "A lot of my sisters are musical, so we sing together and make up songs. It's a lot of us teasing each other – normal things, not just the special things like being on a red carpet."

They've got one thing in common with Carrie Bradshaw"We have a crazy amount of shoes," says Serena, who estimates their collection numbers in the hundreds – in spite of one traumatic experience: "Fifty percent of my shoes were lost on a trip," she says. "This was about a year or two ago. The airline lost my luggage. All my Manolos and Rene Caovillas. Ever since then I've been buying trying to make up for it."

Venus, too, is a bit of a fashionista. "People come up to me and say, 'I didn't know you looked that great,'" she says. "I'm like, 'That's because when you usually see me I'm in the middle of a grunt and screaming and fighting in the middle of a battle.'"